颤藻浓度和水温对凡纳滨对虾响应颤藻粗提液毒性的影响

文章研究了绿色颤藻(Oscillatoria chlorina)不同成分对凡纳滨对虾(Litopenaeus vannamei)的毒性,分析了颤藻浓度与水温对对虾响应粗提液毒性的影响,并初步检测了颤藻粗提液所含的毒素。结果显示,湿藻质量浓度为5.04 mg·m L~(-1)的颤藻细胞及其粗提液可导致93.72%以上的对虾死亡,藻细胞培养液对对虾无致死效应。用湿藻质量浓度高于2.52 mg·m L~(-1)的粗提液注射对虾,对虾死亡率超过86.67%,随质量浓度低至0.504 mg·m L~(-1),对虾死亡率降至2.22%,差异显著(P0.05);水温显著影响了粗提液对对虾的致死效应(P0.05),湿藻质量浓度为2.52 mg·m L~(-1)的粗提液在22℃水温条件下可引起20.0%对虾死亡,当温度升至34℃,对虾死亡率增加至97.8%;以微囊藻毒素(Microcystin-RR/YR/LR,MC-RR/YR/LR)作标准品,使用高效液相色谱法检测颤藻粗提液毒素,结果在粗提液中均未检出RR、YR、LR等3种常见的微囊藻毒素。结果表明,绿色颤藻可致对虾急性死亡,其主要有害成分是颤藻粗提液所含的非MC-RR/YR/LR等藻毒素,对虾对颤藻粗提液毒性的响应与颤藻浓度和水温显著相关(P0.05)。

Effect of cell concentration and water temperature on toxicity of Litopenaeus vannamei caused by Oscillatoria chlorina

Different components of Oscillatoria chlorina,including whole cells,crude extracts of cells and cell-free culture medium were injected into Litopenaeus vannamei to study the lethal effect.For the toxicity of crude extracts,the effects of cell concentration and water temperature were evaluated,and toxin of crude extracts was analyzed.The results show that O.chlorina cells and crude extracts could cause massive death of shrimp(death rate≥93.72％),while cell-free culture medium had no effect on the survival of shrimp.The toxicity of crude extracts on shrimp was closely related with cells concentration and water temperature.High concentrations of crude extracts(≥2.52 mg·mL-1)could cause high death rate of shrimp(≥86.67％),and as the concentration dropped below 0.504 mg·mL-1,the death rate also decreased to 2.22％.The death rate of shrimp injected by crude extracts was 97.8％at 34 ℃,which was much greater than that at 22 ℃(20.0％).The crude extracts did not contain microcystin-RR/YR/LR(MC-RR/YR/LR)by the detection of High Performance Liquid Chromatography(HPLC).In conclusion,O.chlorina had acute toxic effect on L.vannamei,which was closely related with cells concentration and water temperature.The toxin mostly existed in crude extracts of O.chlorina,but was not MC-RR/YR/LR.